UK researchers leverage machine learning and DNA barcoding to tackle honey fraud

20 Aug 2024 --- Researchers at Cranfield University in England have developed two new ways to uncover sugar syrup adulteration in honey. These tests utilize light analysis, DNA barcoding and machine learning to enable fast and accurate detection of fake products in the UK.

The honey sector is steadily swelling in the UK, with £89.8 million (US$ 115 million) worth of the commodity imported into the country in 2023. Honey fraud is also on the rise, with sweetening syrups added to dilute the pure form. According to a 2023 report by the European Commission, 46% of 147 honey samples tested were likely contaminated with low-cost plant syrups.

The research, led by Dr. Maria Anastasiadi, a lecturer in Bioinformatics at the university, notes that it can be difficult to detect adulteration in honey due to its different sources of nectar, season of harvest and geography.

While authentication methods can be costly and time-intensive, demands for reliable testing remain strong.

“Honey is expensive and in demand – and can be targeted by fraudsters, which leaves genuine suppliers out of pocket and undermines consumers’ trust. This method is an effective, quick tool to identify suspicious samples of honey, helping the industry to protect consumers and verify supply chains,” says Anastasiadi.

Detecting fake honey

The researchers used a light analysis technique in the first method to trace adulteration in honey jars without opening the lid. They tested various UK honeys laced with rice and sugar beet syrup with non-invasive Spatial Offset Raman Spectroscopy (SORS), a method common in pharmaceutical and security diagnostics.

The technology identified the “fingerprint” of each ingredient in honey and with the help of machine learning, flagged the presence of various plant-based sugar syrups.

This method can simplify testing honey along the value chain, and its portability and ease of implementation make standardization possible.

Tracing honey DNA

The second method — developed in collaboration with the Food Standards Agency and the Institute for Global Food Security at Queen’s University of Belfast — used DNA barcoding.

DNA barcoding effectively broke down the composition of each honey to detect syrups even at a 1% adulteration level.The sample space included 17 honeys collected from bee farmers across the UK to account for different seasons and nectar sources. The scientists also tested four honey samples from supermarkets and online sellers in the region. The team spiked these with rice and corn syrup sourced from different countries.

DNA barcoding effectively broke down the composition of each honey to detect syrups even at a 1% adulteration level.

“To date, DNA methods haven’t been widely used to examine honey authenticity,” says Anastasiadi. “But our study showed that this is a sensitive, reliable and robust way to detect adulteration and confirm the origins of syrups added to the honey.”

“The large variation of honey composition makes it particularly difficult to authenticate. So having this consistent technique in the testing armory could take the sting out of honey fraud.”

Sophie Dodd, a doctoral scholar working on the topic of honey authentication at the university, adds: “It is vital to have samples of known origin and purity to validate the methods, so we want to extend our thanks to the Bee Farmers Association who we work closely with in our projects.”

The researchers note that manufacturers and processors can use the two methods complementarily to increase the chances of detecting exogenous sugar adulteration in honey.

In addition to honey fraud, the EU has recorded a spike in cases of olive oil contamination, where what appears to be extra virgin olive oil is found to be contaminated with cheaper oils and, in some cases, industry-grade oils unfit for human consumption.

According to the FAO, food fraud always concerns the quality of food. It can be related to either the product (e.g., wood dust in coriander) or the process (e.g., selling non-halal products as halal) without intentionally affecting food safety.

By Anvisha Manral